Lesson 14.1

1. Chapter 14: The Urinary System Lesson 14.1 Anatomy of the Kidney

2. Kidney Location and Size

3. Anatomy of the Kidney • Retroperitoneal and fat covered • 11 cm X 3cm X 6cm • 150 gm • renal cortex • Outer, light colored • renal medulla • Middle, darker • Renal pyramids • renal pelvis • Inner, leads to ureter • hollow

4. Anatomy of the Kidney • renal medulla • Pyramid • Base- out • Papilla-in • Columns • Separate • Ureter • One for each • bladder • urethra

5. Nerve and Blood Supply • 20–25% of blood flows to kidneys • renal artery • renal vein • sympathetic nerve system • renal nerve fibers • Mesh around renal artery • Everything connects at the Hilum

6. The Nephron • basic working unit of each kidney • Each kidney has 1 million nephrons • Each nephron has a blood supply and creates urine • two main parts • renal corpuscle • Glomerulus (capillaries) • Glomerular capsule ( collecting cup) • Enters at afferent, exits at efferent (arterioles) • Like a cul-de-sac • renal tubule • processing

8. The Glomerulus • glomerular capsule • outer surface • Podocytesinterlock • filtration slits • wastes sifted out of blood

9. Renal Tubule • proximal convoluted tubule (PCT) • At glomerulus • nephron loop (loop of Henle) • Descending (thin walls) and ascending • distal convoluted tubule (DCT) • collecting duct • Receives from several nephrons • Drains to renal pelvis

10. Blood Flow through the Kidneys • renal artery • afferent arteriole • Glomerulus • Plasma and wastes removed • efferent arteriole • peritubular capillaries or vasa recta • Secondary capillaries • Fluid reabsorption • Venules • renal vein

11. Chapter 14: The Urinary System Lesson 14.2 Urine Formation, Storage, and Excretion

12. Urine Formation • filtration • water and solutes from capillary to glomerular capsular space • reabsorption • water and solutes move from tubule to capillary • secretion • wastes in capillary pushed into tubule

13. Urine Formation

14. Filtration • molecules smaller than 3 nanometers pushed out of blood • hydrostatic pressure • caused by potential energy (high to low) • osmotic pressure • from dissolved substances in water (salt sucks) • pressure controls • constriction of arteries

15. Reabsorption • sodium • actively pumped out by sodium-potassium pump proteins • secondary active transport • glucose, amino acids, ions, vitamins • osmotic pressure • aquaporin channels • Ion movement

16. Reabsorption

17. Secretion • maintain arterial blood pH at 7.4 (active) • hydrogen ions • bicarbonate ions • some drugs secreted • penicillin • aspirin

18. The Renal Medulla • nephron loop • descending loop • reabsorb water • ascending loop • reabsorb sodium (pump)

19. The Countercurrent Mechanism • Blood flows “down and back”, so does filtrate • vasa recta • movement of blood • nephron loop • movement of filtrate

20. Hormonal Regulation of Urine Volume and Composition • aldosterone • Response to drop in Na or rise in K= more aldosterone • Drop in BP= Renin (hormone) reacts to produce angiotensin to increase pressure • Acts on distal tubule to inc sodium in waste= increased osmosis • atrial natriuretic peptide • Response to increased BP ( atrial stretch) • Blocks sodium reabsorption in collecting ducts • causes urine volume to increase (drop pressure, release water) • antidiuretic hormone • causes urine volume to decrease ( hold water, increase pressure) • Dehydration=high ADH=less urine, Hydration= Low ADH=more urine

21. Urine Storage • ureter • kidney to bladder • Smooth muscle • bladder • stores urine • Transitional cells • Trigone- ureters and urethra • Prostate- men • 500-1000 ml • urethra • bladder to outside body • Smooth muscle/ sphincters • Male 20 cm, Female 3-4 cm

22. Urine Storage

23. Urine Excretion • micturition • Urination • Stretch • Internal • Realize • Voluntary • External • Release

24. Chapter 14: The Urinary System Lesson 14.3 Diseases and Disorders of the Urinary System

25. Assessing Renal Function • physical characteristics of urine • pH range 4.5–8.0 • spG 1.003 to 1.035 • 0.5-2 L/day • chemical composition of urine • 95% water, 5% waste • Urea, Nitrogen, ions • glomerular filtration rate • estimate with creatinine concentration in blood • Muscle metabolism byproduct, quickly filtered

26. Diabetes • diabetes mellitus • glucose in urine- osmosis is the reason! • type I, type II • Proteinuria, ketoacidosis and renal failure. • diabetes insipidus • large amount of dilute urine (>12L spG <1.002) • ADH not made or not used • Common in low Hcg (dwarfism)… Remember?

27. Normal Blood Glucose and Blood Insulin Levels • carbohydrate digestion leads to an increase in blood glucose level • increase in blood glucose level causes the pancreas to secrete insulin • increase in blood insulin level causes • liver glucose uptake • liver conversion of glucose to glycogen • skeletal muscle glucose uptake • skeletal muscle conversion of glucose to glycogen

28. Chronic Kidney Disease • kidney damage • glomerular filtration rate less than 60 ml/min for at least 3 months • develops slowly • Usually diabetes related • When GFR drops to <15ml/min= renal failure • Waste product accumulation, pH uncontrolled, only dialysis or transplant will keep alive • Dialysis becomes more frequent, more health effects. Why?

29. Renal Dialysis- remove H20, urea and Na • hemodialysis • Dialyzer- artificial kidney (external) • peritoneal dialysis • dialysis solution introduced via port to AP cavity • peritoneum acts as dialysis membrane

30. Diseases and Disorders of the Urinary System • kidney stones (pelvis) • calcium, magnesium, or uric acid • <5mm can pass • Lithotripsy- US waves to break stones apart • Fluids good….. • urinary tract infection • Bacteria up urethra to bladder • cystitis • more common in women than men • Can go to kidneys if untreated= pyelonephritis+ back pain